Why we’re building a carbon removal marketplace on Ethereum

Ross Kenyon
Published in
5 min readNov 26, 2018


If you’re totally new to blockchains, first read this article by my colleague Paul Gambill, “Why a carbon market belongs on the blockchain”, and then my piece “Why Nori needs its own cryptocurrency token”.

Choice of platform is a biggie. There are many blockchains competing for applications to build on them. There are design tradeoffs around speed, security, voting, programming language, degrees of decentralization, size/skill/vibrancy of the development community, and other axes. At Nori, we chose Ethereum.

The logo of Ethereum.

Intro to Ethereum

Ethereum is a blockchain that specializes as a smart contract platform. Smart contracts are agreements that are programmed as software: when x happens, y happens. Imagine for instance, placing funds in escrow when buying a house but instead of an escrow agent being paid for that verifying action it took place within software at a fraction of the price. That’s a basic application of a smart contract.

Ethereum is also considered a world computer: when a smart contract is executed, it happens across the thousands of nodes worldwide that process the transaction. Once it is on the blockchain, it becomes extremely costly to change, and is transparent to anyone with an internet connection.

There are many features of Ethereum’s design choices and its community that made this decision for Nori’s carbon removal marketplace a relatively easy one.

Proof of stake

One of Nori’s most common questions is “why have a carbon market on a blockchain given blockchains are responsible for so much energy use?” When people point this out, they’re referring to a particular way of verifying transactions within a blockchain network called proof of work. I will skip the details of how this operates, suffice it to say that proof of work is a method of spending energy to ensure network security. Bitcoin uses proof of work, and Ethereum does too… for now. Ethereum is in the process of switching to proof of stake.

Proof of stake is a type of consensus model that mimics the game theory of proof of work but without all of the electricity being spent in the creation of network security. One could think of proof of stake as a software simulation of proof of work.¹ Ethereum started with a version of proof of work similar to Bitcoin with the intention to transition over to proof of stake. We’re very excited about that transition as we prefer company infrastructure that doesn’t contribute to the problem we’re trying to solve, insofar as such a thing is possible.

Community & Tooling

A good developer can learn what they need to know to get the job done. But some blockchains make it harder than others. For instance, Ethereum is written in JavaScript (though there are implementations in Go, Rust, et al), and its smart contract layer is written in a new language called Solidity. To get up to speed on Solidity you need a vibrant community in StackOverflow where devs can work through problems together. You need resources that have been built as libraries that can plug and play into the application you’re building. Few blockchains have many resources like this. If Ethereum is the Oregon Trail, many of the other blockhains are more at the level of Lewis and Clark.

For instance, as a self-admitted coding noobie, I have been working my way through the amazing CryptoZombies Solidity series. It teaches you the basics of how to build smart contracts in Solidity up to building your own cryptocollectibles program. It’s better than more mainstream attempts to teach coding online that I’ve done. And it’s free.

Well worth your time if you’d like to learn Solidity!

Part of the reason why these resources all exist is because there is such a huge amount of developers working on Ethereum in some capacity. As a popular open-source project there are many eyes on the code that is written and a diverse set of applications built on Ethereum. The network is made stronger with so many people interested in seeing Ethereum grow and succeed.


Newer blockchains make a lot of promises, and I’m certain many will deliver advances over Ethereum on some fronts. They will also face some big hiccups. Ethereum has had an operational headstart of a few years on most of them, so while it isn’t always as flashy as newer blockchains, it’s reliable.


The Ethereum community tends to value using blockchain for social good. Its leaders have been around for years and are in many cases dismissive of the more speculative applications their technology enables. It isn’t just about the money. It’s about better and more just ways of organizing human life. That’s what we at Nori care about too, and why we want to spend our time in this community.


While we are building on Ethereum, we celebrate the achievements of other blockchains which have made alternative design choices. We aren’t partisans. The great thing about the blockchain space is the ease of choosing to support a different project with your funds or development if you do not like the direction a project has gone. The vibrancy of the experiments and the big dreams in this space give us views of new vistas of human cooperation while we build the Nori carbon removal marketplace on Ethereum.

If you’ve read the two pieces at the top of this article and you’d like more technical details, our very own Jaycen Horton has written two outstanding and meme-dense pieces: “An Uncensored Look at Smart Contracts, Part 1: The Gentlest of Introductions”, and “The Journey to a World Unknown Begins in a Vessel Yet Built”.

  1. There’s a lot more to it than this, and in some ways proof of stake is quite different in game theory than proof of work, but I won’t belabor the point for the sake of introductory clarity.



Ross Kenyon

Cofounder of Nori; host of the Reversing Climate Change and Carbon Removal Newsroom podcasts.